SERBIKE MAWAL TCl9i’m‘,:, ”

CAUTION

Before Servicing the chassis. read the “IMPORTANT SERVICE SAFETY INFORMATION” on page 2 of

this manual. ,,:

19’ REMOTE CONTROL COLORTELEVISION WITH ON-SCREENPICTURE CONTROLS

AKB AUTOMATIC KlNE BIAS

CCD CLOSED CAPTION DECODER

SPECIFICATIONS

SPEAKER6KHz 0+/-3db

SIZEE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1/16" 0.33 oz. Magnet VOICE COIL IMPEDANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 ohms at 600HzANTENNA INPUTT IMPEDANCE . . . . . . . . . . . ....75 ohm Coaxial inputRECEIVING CHA N NE L S

UHF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 4 - 6 9

C A T V . . . . . . . . . . . . . .. .

14-22 .23-36 .

. (AA-FFF). .

. .. . Carrier Frequency ................................... 45 .75MHzSound IF Carrier Frequencyy ................... . .................. 41 .25MHzColor S u b - Frequency ................................... 42 .17MHz

WEIGHT ........................................................................ 38 l b sDIMENSIONSS .......................

CONTENTS

IMPORTANT SERVICE SAFETY INFORMATION ................... 2ELECTRICAL ADJUSTMENTS

1. BEFORE MAKING ELECTRICAL ADJUSTMENTS1-1. PREPARE THE FOLLOWING MEASUREMENT

TOOLS FOR ELECTRICAL ADJUSTMENTS .... 32. BASiC AOJUSTMENTS

2-1. VIF ANDD AFT . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32-2: BRIGHT. AGC. TINT AND COLOR .3. 42.3: CUT OFF . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52-4. FOCUS . . 52-5. VERTICAL SIZE . . . . . . . . . . . . . . . . . . . . 52-6. VERTICAL POSITIONN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . j

2-7. HORIZONTAL POSITION . . . . . . . . . . . . . . . . . . . . 5

3. PURITY AND CONVERGENCE ADJUSTMENT3-1. STATIC CONVERGENCE ROUGH ADJUSTMENTj ... 53.2: PURITYy ............................................................... 53-3. STATIC CONVERGENCE ....................................... 63-4: DYNAMIC CONVERGENCE. ................................. 6

MAJOR COMPONENTS LOCATION GUIDEE ............................ 7SEMICONDUCTOR BASE CONNECTIONSS ............................. 8BLOCK DIAGRAM, .............................................................. 9PRlNTED CIRCUIT BOARDS

M A I N. ...................................................................... 10.. , ,CRT/REMOCONN ............................................................ . 2

SCHEMATIC DIAGRAMSTUNERR .......................................................................... . 2IF/MICON... ................................................................... . 3CHROMA........................................................................ 14DEFLECTIONN .................................................................. . 5POWER/AUDIOO ............................................................ 16

MECHANICAL EXPLODED V I E W. ........................................ . 7MECHANlCAL REPLACEMENT PARTS L I S T . . . . . . . . . . . . . . . . . 8ELECTRlCAL REPLACEMENT PARTS LIST ...... ...-............13. 19

ELECTRICAL ADJUSTMENTS

1. BEFORE MAKING ELECTRICALADJUSTMENTS

Read and perform t h e s e adjustments when repairingthe circuits or replacing electrical parts or PCBassemblies.

CAUTIONUse an isolation transformer when performingany service on lhis chassis.

Before removing the anode cap. dischargeelectricity because it contains high voltage

When removing a PCB or related component.alter unfastening or changing a wire. be sure toput the wire back in its original position.

Inferior silicon grease can damage IC’s andtransistors. When replacing IC’s and transistors.use only specified silicon grease (YG6260M).Remove all old silicon before applying newsilicon.

l-l: Prepare the following measurement toolsfor electrical adjustments

1. Sweepmarker Generator2. Oscilloscope3. Digital Voltmeter4. Color Bar Generator

2. BASIC ADJUSTMENTS

2-1: VIF AND AFT

NOTEConnect input and output terminals of thesweepmarket generator to the circuit as shownin Fig. 2-l-a. then adjust it.

SWEEPMARKERGENERATOR OUTPUT 0.022.uF

SWEEPMARKERGENERATOR INPUT 47KohmIN60 ““E TP

-60 ,GND

I Fig. 2-1

1. Connect output terminal of the sweepmarkergenerator to TP201. (Connect a 2.7K ohmresistor between them.)

2. Connect input terminal of the sweepmarkergenerator t o TP204.

3. Connect a 1OK ohm variable resistor to IF AGCterminal (TP210). 12V line and ground. thenadjust to make the waveform of theoscilloscope readable.

a

1OK ohm12V

77AGC TP210

4. Adjust L205 until the waveform marker (45.75MHz)becomes as shown in Fig. 2-l-b.

5,

6.

7

8.

9

1011

45.75MHz

1

Disconnect output terminal of the sweepmarkergenerator from TP201. then connect it to TPof the tuner pack.Adjust tuner pack coil until the waveformbecomes as shown in Fig. 2-l-c.

41.24MHz

Disconnect the 10K ohm variable resistorand 2.7K ohm resistor.Disconnect input and output terminals of thesweepmarker generator.Connect the AFT adjustment oscillator (45.75MHzlto TP, of the tuner pack through a 2.7K ohmresistor.Connect the digital voltmeter to TP206.Adjust L204 to find the point where the voltageof TP206 changes dramatically. and adjust to4.5VDC at that point.

2-2: BRIGHT, AGC, TINT AND COLOR

On-Screen Display AdjustmentInsert the point o f a straightened paper clip intothe hole on, the remote control marked with anarrow as shown in Fig. 2-2.The adjustment mode display will appear as shownin Fig. 2-3.

3

ELECTRICAL A D J U S T M E N T S

NOTEUse the 1 - 7 keys on the remote control to Selectthe options show” in Fig. 2-3.Press the 7 key to end the adjustments

ADJUSTMENT MODE1. AGC/BRIGHT/TINT/COLOR AUTO2. SUB BRIGHT AUTO3. AGC MANUAL4. COLOR MANUAL5. TINT MANUAL6, BRIGHT MANUAL7. END

cFig. 2-3

2-2-A: BRIGHT

1. Receive the monochrome pattern2. Activate the adiustment mode display and press

the 6 key.3. Press the VOL. UP/DOWN key on the remote

control until 0% of gray scale will begins to lighten.

2-2-B. AGC

NOTEAdjust after performing adjustments in section 2-l

In case of weak electric field.1. Tune to a noisy channel.2. Activate the adjustment mode display and press

the 3 key.3. Press the VOL. UP/DOWN key a” the remote control

until noise is at minimum.4. Change the channel. confirm other channels

are normal.

I” case of strong electric field.(Radio frequency interlerence can cause diagonalstreaks to appear.)

1. Aclivate the adjustment mode display and pressthe 3 key.

2. Press the VOL. UP/DOWN key on the remotecont ro l until diagonal streaks are at minimum.

3. If there is still a problem after pressing the VOL.UP/DOWN key on the remote control. installan attenuator to the antenna terminals the”repeat step 1.

4

4. Confirm noise does not appear,5. Change the channel. confirm other channels

are ‘normal.

2-2-C: TINT

1. Receive the color bar patter”.2. Using the remote Control. set the brightness

and color to center position.3. Using the remote control, set the contrast

to maxlmum position.4. Connect the oscilloscope to TPO23.5. Activate the adjustment mode display and press

the 5 key.6. Press the VOL. UP/DOWN key a” the remote

Control until the waveform becomes as show” inFig. 2-4

I

2-2-D: COLOR

1. Receive the color bar patter”,2. Using the remote control, set the brightness

and tint to center position.3. Using the remote control, set the contrast

to max imim position4. Connect the oscilloscope to TP022.5. Activate the adjustment mode display and press

the 4 key.6. Adjust the VOLTS RANGE VARIABLE knob of

the oscilloscope until the range between white100% and 0% is set to 5 scales a” the Screenof Ihe oscilloscope.

7. Press the VOL. UP/DOWN key on the remotecontrol until the red color level is set tothe 4.75th scale (95%) from while 0%.(Refer to Fig. 2-5)

Fig. 2.5

ELECTRICAL ADJUSTMENTS

4. Confirm red and blue c o l o r s5. Adjust the slant of Ihe deflection yoke while

watching the screen. then tighten the fixing screw.

MAGNET SCREW

6 POLE MAGNETS

/ - 4 POLE MAGNETS/ I PURITY MAGNETS

Fig. 3-1

3-3: STATIC CONVERGENCE

NOTEAdjust after performing adjustmenls in section 3-2.

1. Receive the crosshatch pattern from color bargenerator.

2. Combine red and blue of ‘the 3 color crosshatchpattern on the center of the screen by adjustingthe pair of 4 pole magnets.

3. Combine red/blue (magenta) and green byadjusting the pair of 6 pole magnets.

3-4: DYNAMIC CONVERGENCE

NOTEAdjust after performing adjustments in section 3-3.

1. Adjust the differences around the screen by movingthe deflection yoke upward/downward andright/left. (Refer to Fig. 3-2-a)

2. Insert three wedges between the deflection yokeand CRT funnel to fix the deflection yoke.(Refer to Fig. 3-2-b)

Fig. 3-2-e

WEDGE WEDGE

WEDGE(

WEDGE POSITION

Fig. 3-2-b

ELECTRICAL ADJUSTMENTS

2-3: CUT OFF

1. Receive the color bar petter”.2. Using the remote control. set brightness and

contrast to minimum position.3. Connect the oscilloscope to ,TPO24.4. Adjust the screen control until voltage is 150VOC.

(Refer to Fig. 2-6)

--

ON” jiO”Fig. 2-f

2-4: FOCUS

1. Receive the broadcasting signal.2. Adiust the locus control until picture is distinct

2-5: VERTICAL SIZE

1. Receive the crosshatch petter” from the colorbar generator.

2. Adjust the bright and contrast controls untilthe crosshatch patter” is distinct.

3. Adjust VA401 until the center of crosshatchis square.

4. Receive broadcasting signal, the” confirmpicture is normal.

2-6: VERTICAL POSITION

1, Receive the color bar patter”.2. Using the remote control. set brightness and

Contrast Lo maximum position.3. Adjust the value of A429 and R430 until horizontal

line of the color bar comes to approximate centerof the CRT.

NOTELessen the value of R430......Picture will move about

5mm UP.Lessen the value of R429.....Picture will move about

5mm DOWN.R429 and R430 are fixed resistors. Use a variableresistor to determine the optimal value and insertthat value resistor.

2 -7 : HORIZONTAL POSITION

Receive the color bar patter”.Using the remote control. set brightness andcontrast to maximum position.Adjust the value of R444 and C460 until the color widthof both screen edges are equal.Receive the broadcasting signal, the” confirmpicture is normal.

NOTELessen the value of R444......Picture will move right.Lessen the value of C460 ,...,.Picture will move left.R444 and C460 are fixed components. Use a variableresistor or capacitor to determine the optimal valueand insert that value component.

3. PURITY A N D CONVERGENCEADJUSTMENT

NOTE1. Turn the unit on and let it warm up for at

least 30 minutes before performing the followiiigadjustments.

2. Place the CRT surface facing east or west toreduce the terrestrial magnetism.

3. Turn ON the unit and demagnetize with a

degauss Coil,

3-1: STATIC CONVERGENCE (ROUGH ADJUSTMENT

1. Tighten the screw for the magnet. Refer to theadjusted CRT for the position.(Refer t o Fig. 3-1)If the deflection yoke and magnet are in onebody, untighten the screw for the body.

2. Receive the green raster patter” from c o l o rbar generator.

3. Slide the deflection yoke until it touches thefunnel side o f the CRT.

4. Adjust center of screen to green. with redand blue a” the sides, using the pair ofpurity magnets.

5. Switch the color bar generator from the greenraster patter” to, the crosshatch pattern.

6. Combine red and blue of the 3 color crosshatchPatter” on the center of the screen by adjustingthe pair of 4 pole magnets.

7. Combine red/blue (magenta) and green byadjusting the pair of 6 pole magnets.

8. Adjust the crosshatch petter” to change towhite by repeating steps 6 and 7.

3-2: PURITY

NOTEAdjust after; performing adjustments in section 3-1

Receive the green raster petter” from color bargenerator.Adjust the pair of purity magnets to center thecolor on the screen.Adjust the pair of purity magnets so the colorat ends are equally wide.Move the deflection yoke backward (to neckside) slowly, and Stop it at the position whenthe whole screen is green.